The C11 BOB Users Guide says to set the Jumpers for COM (+5VDC or GND) and the Pull Up or Pull Dn but I have no indication which ones I need.

I have no problem setting the jumpers but are any rules to help me establish what I need?

Hi,
whether you require pull-up or pull-down is determined by your hardware.

For instance if have a number of switches wired in series with Normally Closed contacts to 0V, if you have a pull-up resistor the input
will be pulled low (countering the pull-up resistor) UNTIL such time as one of the switches goes open, then the input will be pulled high.
So your choice of pull-up or pull-down is determined by how you want to wire your switches.

Craig

Thanks Craig, I know the answer to my questions doesn’t have a simple answer so all I have to do experiment and hope for the best. Motors wiring is done and I was able to jog the motors, a big relief. Next is tuning the motors and finish the limits/home wiring.

Cheers

Hi,
while the choice of pull-up or pull-down is determined by your hardware its not true that you can set it at will.
Most breakout boards have jumpers that cause a number of inputs to be pulled high (or low), so that the choice you make affects
multiple inputs. If you want one input pulled high but another pulled low, more often than not it can't be done.

I'd recommend that your choice, at least for the outputs, be determined by safety reasons. In particular what happens when when the machine
is powering up, or in the period of time when the machine is powered but Mach is not yet running? What you do not want to happen is the
spindle start up or the machine move.

I presume that you have a relay to turn the spindle ON/OFF?. Then you need to be assured that the relay is inactive, ie spindle off while the machine
and BoB are powering up. Likewise I would suggest that the stepper drives NOT be enabled UNTIL the machine is powered up AND Mach is running.
That is likely to require that the stepper drive Enable signal from the BoB is pulled low, so that at no time are the steppers energised and enabled
WITHOUT Mach being in control.

These safety considerations are likely to determine whether you have a pull-up or a pull-down resistor on your outputs. It may well be that for convienence
that you want a pull-up on a given output to make a pump work correctly say,  but for spindle safety that is not possible, the output must have a pull-down.
Bad luck. Thus for your pump to work as intended you must supply a signal inversion.

Inputs are somewhat less critical.

I posted a picture of my own BoB. I elected to design and build it so that all the inputs (31 of them) are ALL pulled high. Another way of saying tis is that
they are 'sourcing' inputs. That means that the pull-up resistor on each input sources a small current. For the input to be active the switch or whatever
must pull the input low and sink that current. My BoB is all 24V, and it has a 4.7kOhm pull-up resistor on each input, thus the input sources 5mA to each
input circuit. Therefore ALL my input switches must be  low. For example each Limit switch is Normally Closed and switched to 0V. Only if the switch opens,
ie the machine goes out of bounds, does the input go high, thereby indicating a Limit event.

I suppose it is easily possible to have some inputs pulled up (sourcing) while have other pulled low (sinking) but to date I've suffered no problems
with having sourcing inputs only.

Craig

Thanks Craig, I know the answer to my questions doesn’t have a simple answer so all I have to do experiment and hope for the best. Motors wiring is done and I was able to jog the motors, a big relief. Next is tuning the motors and finish the limits/home wiring.

Cheers

Experimenting and hoping for the best is not the right way!  You need to understand what the hardware and software requirements are and work out how to satisfy them.  That way you will learn more and be more likely to succeed.  "Sucking it and see" is not a good strategy in engineering.

Many thanks for the education Craig, its much appreciated,

I know about the jumpers in breakout boards and my problem is that non tells you how to set these jumpers because they only give you the available options but do not tell you what you really need for your hardware so it’s up to you to make a decision on how to set them.

Perhaps my previous explanation was not right because I never set these jumpers at will. I will have to ask in the forums my questions and then I will have to analyze the answers and make my decision on how to set each jumper.

I’m also aware of the state of my cnc before Mach3 takes over and I have wired my E-Stop as hardware disable and it works. For the spindle my wiring is not done yet since it’s the most complicated to do and it will be the last and after all my stepper motors and limits are working.

I read that it’s a good idea to have the 110VAC feeding the spindle on a relay and I plan to do so but I’m not sure if the 3 relays available in my C11G are good for this or I should use a separate relay and this I will decide when the time comes. I will post the relevant info here when I start to work on the spindle wiring and hopefully you can give me a hand if you have the time.

Cheers

Hi,

I read that it’s a good idea to have the 110VAC feeding the spindle on a relay and I plan to do so but I’m not sure if the 3 relays available in my C11G are good for this or I should use a separate relay and this I will decide when the time comes. I will post the relevant info here when I start to work on the spindle wiring and hopefully you can give me a hand if you have the time.

Are you using a VFD? If you are then don't try to switch the power (110VAC or 2390VAC) to it via a relay. VFDs have an input for ON/OFF, use it, all it requires is an isolated set of relay contacts.

Craig

No VFD, I will use a Taig R16 spindle along with a Sherline 90VDC motor which is controlled by a KBIC DC motor speed controller.

I used the same spindle/motor about 11 years ago but then I had the Gecko G540 board and now I have the C11G which is completely different